<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>
</head>

<body>
    <div id="app">
        <h1>{{count}} </h1>

        <button @click="add">累加</button>
        <button @click="decrement($event)">累减</button>
        <button @click="addN(5,$event)">点击加5</button>

    </div>
    <script>
        const vm = new Vue({
            el: '#app',
            data() {
                return {
                    count: 0
                }
            },
            methods: {
                add() {
                    this.count++
                },
                decrement(e) {
                    this.count--
                },
                addN(n, e) {
                    this.count += n
                }
            }
        })
    </script>
</body>

</html>